Barrier



FIG. 1 is a left side view of a barrier, showing my new design, with the right side view being identical;

FIG. 2 is a front view thereof, with the rear view being identical;

FIG. 3 is a top view thereof; and,

FIG. 4 is a front, top and right side perspective view thereof. 

CLAIM The ornamental design for a barrier, as shown and described. 